# `C` is the segment `y=2b+1` for `bin[1,3]` -Use geometry to calculate the area of the surface obtained by rotating `C` about the b-axis

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The segment C is given by y = 2b + 1 for b in [1, 3].

The surface area of the surface obtained by rotating C about the b-axis is equal to `pi*7*sqrt(7^2 + 3^2) - pi*3*sqrt(1^2 + 3^2)`

=> `pi*(7*sqrt 58 - 3*sqrt 10)`

**The surface area obtained by rotating the segment about the b axis is **`pi*(7*sqrt 58 - 3*sqrt 10)`